Sulphapyridine sodium

Fenfluramine Hydrochloride Clorprenaline Hydrochloride Lysergic Acid Stilboestrol Dichlorophen Bufylline Orphenadrine Meptazinol Hydrochloride Methylphenidate Hydrochloride Halazone Sulphamethizole Tolbutamide Doxylamine Hexoestrol Oestrone Mecloqualone Nordazepam Chloroprocaine Medazepam Carbutamide Normorphine Pilocarpine Nitrate Sulphapyridine Sodium Cyclazocine Dextromethorphan Methoprotryne Meprylcaine Hydrochloride Procainamide Hydrochloride Muzolimine Clorgyline... 

Sulphanilylacetamide, 981 Sulphanilylurea, 995 Sulphaphenazole, 992 Sulphaphenylpyrazol, 992 Sulphapyridine, 992 (metabolite), 994 Sulphapyridine sodium, 993 Sulphapyridine, soluble, 993 Sulphaquinoxaline, 980 Sulphasalazine, 993 Sulphasomidine, 994 Sulphasomizole, xvii Sulphate conjugation, 291 Sulphathiazole, 995 (metabolite), 900, 978 Sulphathiazole sodium, 995 Sulphathiazole, soluble, 995 Sulphatriad, 979, 982, 995 Sulphaurea, 995 Sulphide, 68 Sulphinpyrazone, 996 Sulphinpyrazone sulphide, 996 Sulphinpyrazone sulphone, 996 Sulphonal, xvii Sulphonamides, colour test, 131 gas chromatography, 200... 

Hydrolyse the acetyl-sulphap3Tidine by boiling it with 10 parts of 2N sodium hydroxide for 1 hour, and allow to cool. Precipitate the base by the addition of 50 per cent, acetic acid until the mixture is just acid to litmus (pH about 6 5) avoid a large excess of acid. Filter off the crude sulphapyridine, wash well with water, and dry at 90° to constant weight (about 12 hours any acetate formed will bo decomposed). The yield is 35 g. RecrystaUise from 90 per cent, acetone (5) the recovery of the pure compoimd, m.p. 190-191°, is about 80 per cent. 

An alternative method of purification, well adapted for large scale practice, is as follows. Dissolve the crude sulphapyridine in 1-05 mols of 30 per cent. u>/v sodium hydroxide, salt out the sodium derivative with excess of sodium chloride,... 

Cool and filter. Dissolve in the minimum volume of hot water, treat with about 0-5 per cent, by weight of decolourising carbon, filter, precipitate the base with 50 per cent, acetic acid imtil just acid to litmus (avoid an excess of acid), filter off the sulphapyridine at the pump, wash thoroughly with hot water, and dry to constant weight at 90° (about 12 horirs). Alternatively, the cold solution of the sodium salt may be just acidified with dilute hydrochloric acid with very vigorous stirring the presence of a local excess of acid must be avoided since sulphapyridine is hydrolysed by mineral acids to sulphanilic acid and 2-aminopyridine. 

Fig. U Example of the bibliographic entries in the PDF for substances listed by compound name. Each name is followed by the formula and the d-spacings of the three strongest diffraction hnes, with the relative intensity as a subscript. The last column on the right is the card number in the PDF. Multiple entries with different principle lines are indications of polymorphic systems, for instance the three entries for sulphapyridine and sulphathiazole, the four entries for sulphanilamide and the two entries for sulphathiazole sodium hydrate, but additional bibliographic and crystallographic information should be obtained from the entries themselves.

Because of the limited solubility of the xanthine derivatives in water, their solubilization by hydrotropes has been the subject of much interest. Such diverse compounds as piperazine [279], sodium salicylate [280], adenosine [281], and diethanolamine [282] have been used to solubilize theophylline. The action of each is presumably due to complex formation. Neish [283] found that caffeine, a xanthine derivative, increased the solubility of a number of aromatic amines, including sulphapyridine, sulphathiazole, and certain dyes. 

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